Vanishing of the James brace product before rationalization for two classes of fibrations
Determine whether the James brace product { , }_s vanishes identically in the original (non-rationalized) fibration in each of the following settings: (i) an S^n-bundle S^n ↪ E → X with a homotopy section s, where X is simply connected and n > 1 is odd; and (ii) an S^k-bundle S^k ↪ E → G with a homotopy section s, where G is a simply connected compact Lie group and k > 1. Concretely, ascertain whether {α, β}_s = 0 for all α ∈ π_i(X) and β ∈ π_j(S^n) in case (i), and for all α ∈ π_i(G) and β ∈ π_j(S^k) in case (ii), without passing to rationalization.
References
In the above two examples, we do not know whether the James brace product vanishes at the fibration level itself (before taking the rationalization).
— On the James brace product: Generalization, relation to $H$-splitting of loop space fibrations & the $J$-homomorphism
(2401.16206 - Basu et al., 29 Jan 2024) in Section 5 (Localization of Spaces and Brace Product)